Question

The correct statement is/are (A) Alkyl halide can be used as solvents for relatively non-polar compounds (B) Halothane is used as an anesthetic (C) A halogen atom on \(\mathrm{sp}^{2}\) carbon is always defined as aryl halide (D) A halogen atom on \(\mathrm{sp}^{3}\) carbon atom is defined as alkyl halide

Short answer

The correct statements are (A), (B), and (D). Alkyl halides can be used as solvents for relatively non-polar compounds, halothane is used as an anesthetic, and a halogen atom on an \(\mathrm{sp}^{3}\) carbon atom is defined as an alkyl halide.

Step-by-step solution

Analyzing statement (A)

In statement (A), it is mentioned that alkyl halides can be used as solvents for relatively non-polar compounds. Alkyl halides are molecules where halogens are attached to an alkyl group. Since halogens are relatively more electronegative than their connecting alkyl groups, alkyl halides have a polar nature. However, some alkyl halides can indeed be used as solvents for relatively non-polar compounds due to their similar molecular structure. So, statement (A) is correct.

Analyzing statement (B)

Statement (B) states that halothane, a compound in which halogens (specifically, fluorines and chlorines) replace hydrogen atoms on ethane, is used as an anesthetic. This is a well-known fact, and halothane has seen usage in general anesthesia for decades. Thus, statement (B) is also correct.

Analyzing statement (C)

Statement (C) claims that a halogen atom on an \(\mathrm{sp}^{2}\) carbon atom is always referred to as an aryl halide. Aryl halides are compounds that consist of a halogen atom connected to a carbon atom belonging to an aromatic ring (benzene, for example) that exhibits an \(\mathrm{sp}^{2}\) hybridization. Although this statement is true for molecules containing aromatic rings, it is not necessarily true for all molecules with an \(\mathrm{sp}^{2}\) carbon atom. Thus, statement (C) is incorrect.

Analyzing statement (D)

In statement (D), it is mentioned that a halogen atom on an \(\mathrm{sp}^{3}\) carbon atom is defined as an alkyl halide. Alkyl halides are compounds in which a halogen atom is connected to an alkyl group, which has an \(\mathrm{sp}^{3}\) hybridized carbon atom. Therefore, statement (D) is correct. Based on the analysis of each statement: The correct statements are (A), (B), and (D).

Key concepts

Alkyl Halides

Alkyl halides, also known as haloalkanes, play an integral role in organic chemistry and industrial applications. These are organic compounds where one or more halogen atoms (fluorine, chlorine, bromine, or iodine) are bonded to an alkyl group. An alkyl group is a fragment of a molecule with general formula CnH(2n+1), derived from an alkane by removing one hydrogen atom.

The property of being relatively polar allows alkyl halides to function as solvents for non-polar compounds, despite their own polar nature. This is because the molecular structure of alkyl halides is sufficiently compatible with non-polar substances to dissolve them effectively, making them useful in various chemical processes.

A typical alkyl halide structure would look something like this:\[ R-X \]where R represents the alkyl group and X represents the halogen atom.

Examples in Daily Life and Industry

• Cleaning and degreasing agents often contain alkyl halides due to their ability to dissolve organic substances.
• Some refrigerants are composed of alkyl halides because of their phase change properties.

While versatile, alkyl halides must be handled with care, as many can be toxic or harmful to the environment.

Halothane Anesthetic

When it comes to surgical procedures, anesthetics are crucial, and halothane is a particularly noteworthy halogenated ether. Halothane, chemically known as 2-bromo-2-chloro-1,1,1-trifluoroethane, was once a widely used anesthetic due to its potency and rapid induction of anesthesia.

The molecular formula for halothane can be represented as:\[ C_2HBrClF_3 \]For decades, halothane revolutionized surgical medicine by offering a safer and more controlled way to induce unconsciousness and manage pain during surgery. Its primary effect is on the central nervous system, where it depresses neuronal activity, leading to a reversible loss of consciousness.

Past and Present Use

• Although its use has declined due to associated risks like liver toxicity and its effects on heart rhythms, halothane was the standard in delivering general anesthesia for a long time.
• It is still used in certain parts of the world, particularly in pediatric anesthesia, due to its less irritating nature for small airways.

The effectiveness of halothane has paved the way for the development of newer, safer anesthetic agents, illustrating the progress in medical pharmacology.

Aryl Halide

Aryl halides are another category of organic compounds significant in synthetic chemistry. These molecules consist of a halogen atom bonded to an aromatic ring carbon that is characteristically sp² hybridized. This class of compounds is represented by the general formula Ar-X, where Ar denotes the aromatic ring and X is the halogen atom.

Possessing a planar ring structure along with a delocalized electron system, aryl halides exhibit unique reactivity patterns compared to alkyl halides, like undergoing electrophilic aromatic substitution rather than the nucleophilic substitution reactions common to alkyl halides.

Characteristics and Applications

• Aryl halides are utilized as intermediates in the dye and pharmaceutical industries due to their versatility in various chemical reactions.
• They are typically more resistant to undergoing nucleophilic substitution reactions, making them less reactive than their alkyl halide counterparts.

Understanding the difference between aryl and alkyl halides is vital for students and professionals working in organic chemistry, as it influences how these compounds are manipulated in chemical syntheses.